Dear Home Assistant Community,
First of all, thank you to everyone who has supported the HS1SA-E Plus smoke alarm over the past months.
We truly appreciate all the feedback, feature requests, testing, bug reports, and discussions from this community. Several community members have helped us test new functionality and integrations, and many of the improvements we have made were directly inspired by your suggestions.
Following the success of the HS1SA-E Plus, we are excited to introduce our latest safety device:
HS1CA-E Plus
A Smart Zigbee Carbon Monoxide Alarm designed with Home Assistant users in mind.
Our goal is not only to provide a reliable CO alarm, but also to offer deeper visibility, control, and automation capabilities that integrate naturally into the Home Assistant ecosystem.
Designed for Long-Term Use
User-Replaceable Battery
Unlike many sealed-battery safety devices, the HS1CA-E Plus features a user-replaceable battery design.
When the battery reaches the end of its life, users can simply replace the battery instead of replacing the entire alarm.
Benefits include:
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Lower long-term ownership cost
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Reduced electronic waste
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Longer product lifespan
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Easier maintenance and servicing
Battery level is reported to Home Assistant, allowing users to receive low-battery notifications before replacement is needed.
OTA Firmware Upgrade Support
The HS1CA-E Plus platform has been designed with future improvements in mind.
some functionality enhancements can be delivered through OTA firmware updates, allowing existing users to benefit from future features and improvements without replacing their devices.
As we continue to receive feedback from the Home Assistant community, we will evaluate new feature requests and add functionality whenever technically possible.
Just as we did with the HS1SA-E Plus, community feedback will continue to influence future development.
Ready for Home Assistant
We know that many Home Assistant users would rather spend their time building automations and experimenting with new ideas than troubleshooting device support.
For that reason, we worked closely with the community to ensure that the HS1CA-E Plus is fully supported by both ZHA and Zigbee2MQTT.
Support has already been completed and merged, and starting with Home Assistant OS 2026.7, the device works out of the box in supported installations.
No custom firmware.
No custom converters.
No custom quirks.
Simply pair the device and start building automations.
Spend your time building automations, not debugging integrations.
Features Inspired by the Community
Remote Self-Test
Perform a complete alarm self-test directly from Home Assistant without physically pressing the test button.
Remote Mute (Hush)
Silence nuisance alarms remotely after verifying that conditions are safe.
Automation-Controlled Siren
Trigger the built-in siren directly from Home Assistant automations.
Example use cases:
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Smoke alarm activated
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Elevated CO levels detected
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Whole-home emergency notifications
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Security and safety automation scenarios
Real-Time CO Concentration Monitoring
View carbon monoxide concentration directly in Home Assistant and use the values in automations, dashboards, and notifications.
Temperature Monitoring
Monitor ambient temperature around the detector.
Heartbeat LED Control
Enable or disable the status LED, especially useful for bedrooms and sleeping areas.
Tested With
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Home Assistant
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ZHA
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Zigbee2MQTT
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Node-RED
In Z2M:
In ZHA:
Example Automations
Garage Protection
When carbon monoxide exceeds a configured threshold:
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Trigger local alarm
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Send mobile notifications
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Start ventilation systems
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Turn on warning lights
Whole-Home Safety
When any smoke or CO alarm is triggered:
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Activate additional Smoke Alarms, CO Alarms, or Heat Alarms
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Flash smart lights throughout the home
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Send emergency notifications
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Trigger custom safety automations
A Shared Platform Across Our Safety Devices
One lesson we learned from the HS1SA-E Plus project is that Home Assistant users often want more than basic alarm reporting. They want visibility, automation, diagnostics, and the flexibility to build their own workflows.
For this reason, the HS1CA-E Plus is not a standalone effort.
Our goal is to bring a similar level of integration and advanced functionality across our entire safety product lineup, including:
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Smoke Alarms
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Carbon Monoxide Alarms
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Heat Alarms
Where hardware capabilities allow, we aim to provide a consistent feature set across devices, including:
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Remote Self-Test
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Remote Mute (Hush)
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Automation-Controlled Sirens
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Heartbeat LED Control
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Additional Diagnostic Information
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OTA Firmware Upgrades
We understand that Home Assistant users enjoy building their own automations and safety workflows. Supporting those DIY use cases is an important part of our product philosophy.
Looking for Feedback
As with the HS1SA-E Plus, community feedback plays an important role in shaping future features.
We would love to hear your thoughts:
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What automations would you use with a CO alarm?
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Which additional diagnostic information would be useful?
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Are there other Home Assistant integrations or features you would like to see?
We view this as an ongoing collaboration with the community rather than a finished product release.
If you have ideas for new features, integrations, or automation scenarios, we would love to hear them.
We will continue listening, improving, and delivering updates whenever technically possible through future OTA firmware updates.
Thank you again for helping us build smarter and safer devices for the Home Assistant ecosystem.
We look forward to hearing your feedback and continuing to improve together with the community.